5. Nails go into wood because of

g You observed the formation of several precipitates in the Reactions in Solution lab exercise. Identify the precipitate in each

RUDIKE [14]

Answer:

For a: Lead iodide is a yellow precipitate.

For b: Barium sulfate is a white precipitate.

For c: Ferric hydroxide is a brown precipitate.

For d: Copper (II) hydroxide is a blue precipitate.

Explanation:

Precipitation reaction is defined as the reaction where a solid precipitate (solid substance) is formed at the end of the reaction. It is insoluble in water.

For the given options:

For (a):

The chemical reaction between KI and lead (II) nitrate follows:

$2KI(aq)+Pb(NO_3)_2(aq)\rightarrow PbI_2(s)+2KNO_3(aq)$

The iodide of lead is generally insoluble in water. Thus, lead iodide is a yellow precipitate.

For b:

The chemical reaction between barium chloride and sulfuric acid follows:

$BaCl_2(aq)+H_2SO_4(aq)\rightarrow BaSO_4(s)+2HCl(aq)$

The sulfate of barium is insoluble in water. Thus, barium sulfate is a white precipitate.

For c:

The chemical reaction between NaOH and ferric chloride follows:

$3NaOH(aq)+FeCl_3(aq)\rightarrow Fe(OH)_3(s)+3NaCl(aq)$

The hydroxide of iron is insoluble in water. Thus, ferric hydroxide is a brown precipitate.

For d:

The chemical reaction between NaOH and copper sulfate follows:

$CuSO_4+2NaOH\rightarrow Cu(OH)_2+Na_2SO_4$

The hydroxide of copper is insoluble in water. Thus, copper (II) hydroxide is a blue precipitate.

6 0

3 years ago

How do you know the ph level of 10^-8

sergiy2304 [10]

pH=6.98

Explanation:

This is a very interesting question because it tests your understanding of what it means to have a dynamic equilibrium going on in solution.

As you know, pure water undergoes self-ionization to form hydronium ions, H3O+, and hydroxide anions, OH−.

2H2O(l]⇌H3O+(aq]+OH−(aq]→ very important!

At room temperature, the value of water's ionization constant, KW, is equal to 10−14. This means that you have

KW=[H3O+]⋅[OH−]=10−14

Since the concentrations of hydronium and hydroxide ions are equal for pure water, you will have

[H3O+]=√10−14=10−7M

The pH of pure water will thus be

pH=−log([H3O+])

pH=−log(10−7)=7

Now, let's assume that you're working with a 1.0-L solution of pure water and you add some 10

5 0

3 years ago

Plz help I’m pretty confused on this question

sergeinik [125]

Answer:

Bohr model A

Explanation:

It has more valance electrons therefore has more interaction between the atoms and has more electronegativity.

7 0

3 years ago

Select the molecule where free rotation around one or more bonds is not possible. Group of answer choices N2H4 C2Cl4 NH3 C2H6 CC

Alexandra [31]

Answer:

C₂Cl₄

Explanation:

To know if free rotation around a bond in a compound is possible, we need to see the structure of the compound (picture in attachment).

In single bonds, which are formed by σ bonds, the atoms are not fixed in a single position, and free rotation is permitted.

Double and triple bonds are formed by a σ bond and one or two π bonds, respectively. These bonds do not allow rotation, since it is not possible to twist the ends without breaking the π bond.

The chloroethylene (C₂Cl₄) has two carbons with an sp2-sp2 hybridization, they are bonded together by a double bond. Free rotation on this bond is not possible, because six atoms, including the carbon atoms, doubly bonded and the four chlorine atoms bonded to them, must be on the same plane.

4 0

3 years ago

According to the law of conservation of mass, what is the same on both sides of a balanced chemical equation?

Firlakuza [10]

According to the law of conservation of mass, what is the same on both sides of a balanced chemical equation?

A. the volume of the substances

B. the subscripts

C. the total mass of atoms

D. the coefficients

Answer:

A balanced equation demonstrates the conservation of mass by having the same number of each type of atom on both sides of the arrow.

Explanation:

Every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. ... Use coefficients of products and reactants to balance the number of atoms of an element on both sides of a chemical equation.

Consider the balanced equation for the combustion of methane.

CH

4

+

2O

2

→

CO

2

+

2H

2

O

All balanced chemical equations must have the same number of each type of atom on both sides of the arrow.

In this equation, we have 1

C

atom, 4

H

atoms, and 4

O

atoms on each side of the arrow.

The number of atoms does not change, so the total mass of all the atoms is the same before and after the reaction. Mass is conserved.

Here is a video that discusses the importance of balancing a chemical equation.

8 0

3 years ago